1. Field of the invention
This invention relates generally to an adapter, and more particularly to an adapter designed to enable a battery whose shape and dimensions are non-standard, to be housed in an electric appliance which has a battery compartment designed to house a standard battery such as type U1, U2 or U 3.
2. Description of the prior art
Vigorous development is now under way in nickel-cadmium (Ni-Cd) batteries. Particularly, Ni-Cd batteries with valves to release gas produced during overcharging are very convenient when used in various applicances because of low internal voltage drop due low internal resistance, rapid charging (about 5 to 15 minutes), and dischargeability to the extent that the terminal voltage drops, approach zero.
However, Ni-Cd batteries of this type are characterized by small size, large current capacity and rapid charging, and usually have different shape and dimensions from standard batteries such as the U1, U2 and U3 types.
However, it would not be desirable to modify, only for this reason, the battery compartment of an electric appliance which was originally designed to house standard batteries. This might lead to substantial changes in the design of the electric appliance in some cases. Therefore, it is desirable to enable non-standard batteries to be housed in battery compartments designed for batteries of standard shape and dimensions by adding an adapter terminal to the aforementioned non-standard batteries. Meanwhile, in view of the fact that electric appliances which can house non-standard batteries such as the aforementioned Ni-Cd batteries and chargers for such batteries have been successfully developed, it would not be desirable to permanently contain such batteries in a dummy container of standard shape and dimensions.
It is sometimes desired to use or charge the Ni-Cd batteries outside of a dummy container.